At his age ,there is no way imo he should be considering an op. The failure rate is huge, esp at his at his age.Youtube has heaps of exercises for this problem, at 75, resistant bands and gentle exercise are the go. Big plus if you can find a decent physio but not essential. Tore my Rotator Cuff completely 10 years ago, decided against surgery and I'm good as gold . Weights 5 times a week + cardio, no problems. I still do the resistance band exercises. Good luck.